Fertilization is one way to promote rapid recovery of worn turf areas on athletic fields. But time is running short to restore the grass, according to LSU AgCenter horticulturist Dr. Tom Koske.

"Nitrogen is the key element for turfgrass growth. It promotes rapid recovery of wear damage," the LSU AgCenter horticulturist says, but cautions, "Excessive nitrogen levels within the turf result in soft, succulent turf more prone to tearing."

Koske notes that high nitrogen also favors shoot growth and depresses root growth. "Good roots are the key to sustainable athletic turf," he says, adding, "We first concentrate on growing roots; the shoots will usually follow strong and repair well from wear and damage."

The amount of nitrogen to apply also depends on the soil type and on weather conditions. Koske says it is not unusual to use 5 to 7 pounds of nitrogen per 1,000 square feet annually on our native soil bermudagrass. He advises that the maximum nitrogen rate per application should not exceed 1 pound of nitrogen per 1,000 square feet.

"The most effective way to promote recovery of worn turf areas is to use fertilizers with quick release nitrogen sources like ammonium nitrate or urea," Koske says. He recommends applying them at low rates (0.5 pound nitrogen per 1,000 square feet) every two to three weeks during the most active period growth, which is April through September.

If you have areas of extremely high wear, such as mid field, goal mouths and base path edges, treat these areas separately. They may do best with special attention. Spot treating worn areas also extends your fertilizer budget.

Have soil tested annually by the LSU AgCenter. Apply fertilizer containing other nutrients based on soil tests. Apply little or no phosphorus fertilizer if it is not suggested by the soil test recommendations, since phosphorus levels are often sufficient in most managed soils.

Potassium (K) may be applied at rates up to those used for nitrogen, even though lower rates are often adequate. Potassium increases wear tolerance indirectly by increasing turfgrass tolerance to physiological stresses caused by the environment such as drought.

"Stop fertilizing in September, but end with some potassium," Koske says, adding, "And remember, anything can wear out."